Null observation of NLC on July 6/7 2008 twixt 22:38 & 22:53 UT. I had a clear slot between Az 310 to Az 50 and Capella just in & out of the cloud base. Unusual for me as normally cloud would be sat over where the phenomena should be (e.g. Venus transit in Cyprus - one cloud all week - over the sun at ingress !! ). Would have prefferred an NLC display last night but it was not to be.
I think the important thing to realise is that the forum is a continually evolving beast... Last years season didn't see us reporting null observations, this year we have started - admitedly not a common format, but I would suspect in this years null observations their are some that can be used for scientific purposes. Like I say we're learning as we go along here - maybe for next season we'll all be reporting to a common form and format. We're a keen bunch who all work together so anything is possible
From what I can tell there are no detailed guidelines on this. At the moment I'd go with the recommendation in Mike Gadsden's handbook: 'It is important to record also the fact of absence of noctilucent cloud, when the observing conditions are good'. Some NLC observers do indeed include monthly weather reports from their observing site but I'd suggest leaving this optional, at the observer's discretion.
Null obs for me 7/8 july - had the tiniest of slithers of northern horizon visible about 22.00ut - but no nlc visible then. Apart from that, rain, rain, and more rain, atleast it will do the garden good...
Null observation of NLC on July 19/20 2008 between 22:30 & 22:45 UT at Elland in West Yorkshire . Pity re the NLC as practically no cloud and a fairly transparent atmosphere with only the moon to contend with . As the moon gets away towards the end of this month visual and video meteor sessions should be under way .This should give me sufficient to keep me awake and alert !!! Len E